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Maastricht beds which are wholly absent in England, and which 

 on account of their fossils partaking to some extent of an Eocene 

 as well as a cretaceous character are peculiarly interesting. The 

 lecturer pointed out the reasons which induce geologists to regard 

 the Maastricht beds as belonging to the cretaceous system which 

 is most developed in Belgium, in the province of Limburg. This 

 portion of the chalk, which is missing in England, is divided into 

 three groups — the Pisolitic, the Faxoe, and the Maastricht beds. 

 The Faxoe series contains numerous cephalopods, and there 

 can be no doubt about its belonging to the cretaceous age. The 

 Pisolitic beds, represented in the limestones of the Paris basin^ 

 rest unconformably on the white chalk, and are entirely without 

 cretaceous fossils, indicating that a considerable lapse of time 

 must have occurred between the two depositions. The Maastricht 

 beds consist of several different series, which repeat themselves 

 continually ; the main member, which is termed crai iuffeau, is a 

 coarse, yellowish, sandy limestone. Thin beds containing 

 Bryozoa, also frequently recur showing that the periods of similar 

 conditions must have been frequent, probably periods of clearer 

 water, alternating with periods of muddy water. 



]Mr. Nelson gave an interesting account of his visit to the 

 remarkable galleries of the Maastricht quarries. They ramify for 

 ten or twelve miles through the hills in every direction, and are 

 from 15 to 20 feet high. They are believed to have been exca- 

 vated by the Romans, the marks of their pickaxes remaining in 

 the lower portions. The mediseval and modern quarrymen have 

 discarded the pickaxe for the saw, the stone being soft until it is 

 exposed to the external air. Mr. Nelson described the chief 

 objects of interest in these far-reaching galleries. The air is 

 nearly always at uniform temperature, and so dry that the bodies 

 of unfortunate men who have strayed away and been lost in the 

 distant recesses have dried up into mummy-like shapes. The 

 Maastricht fossils are partly cretaceous and partly tertiary, the 

 former preponderating. The three non-British divisions were 

 probably in part synchronous, limestones being formed over the 

 whole district, while the sea varied in temperature and clearness, 

 and slightly in the life it contained. The most remarkable fossil 

 remains are those of the Mosasaurus a huge marine creature like 

 a paddled sea-serpent. 



Mr. Nelson entered fully into geological details, and exhibited 

 several characteristic fossils from the Maastricht beds. 



DECEMBER. 



Extinct Elephants of Kent, by Captain McDahin. 



The portion ofa very fine tusk of a Mammoth which has recently 

 come into the possession of the vicar of Herne-hill (the Rev. F. 



